Feeding apparatus for wire and like elongated material

ABSTRACT

Wire or like elongated material is fed forward in uniform increments by jaws mounted on a slide which is reciprocated in the direction of wire elongation by a crank drive. The jaws are opened and closed in synchronization with the slide movement by an operating member longitudinally slidable in the hollow connecting rod of the crank drive and carrying a cam follower which engages a radial cam fixed on the crank pin of the drive. Movement of the operating member is transmitted to one of the jaws by a wedge-shaped cam on the operating member engaging a cam follower on the movable jaw.

United States Patent Bihler [54] FEEDING APPARATUS FOR WIRE AND LIKEELONGATED MATERIAL [72] Inventor:

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[73] Assignee: Otto Bihler KG, I-Ialblech-Fussen, Germany [22] Filed:July 1, 1971 [2]] Appl. No.: 158,694

[30] Foreign Application Priority Data Otto Bihler, I-lalblech-Fussen,Ger- 7 Sept. 12, 1972 3,486,676 12/1969 Bruns ..226/ 165 X PrimaryExaminer-Allen N. Knowles Attorney-Kelman and Berman [5 7] ABSTRACT Wireor like elongated material is fed forward in uniform increments by jawsmounted on a slide which is reciprocated in the direction of wireelongation by a crank drive. The jaws are opened and closed insynchronization with the slide movement by an operating memberlongitudinally slidable in the hollow connecting rod of the crank driveand carrying a cam follower which engages a radial cam fixed on thecrank pin of the drive. Movement of the operating member is transmittedto one of the jaws by a wedgeshaped cam on the operating member engaginga cam follower on the movable jaw.

9 Claims, 2 Drawing Figures PATENTEDSEP 12 1912 saw 1 or 2 INVEITGROfi'o 3/h/u BY WM M M,

AGENTS PATENTEDSE 2 I972 3.690.533 sum 2 or 2 INVE NTOR Of /'0 75/6 1FEEDING APPARATUS FOR WIRE AND LIKE ELONGATED MATERIAL This invention isconcerned with feeding apparatus for wire and like elongated, andnormally endless, material which is advanced in small, equal incrementstoward a tool or the like.

It is known to provide such a feeding apparatus with a slide guided inthe direction of material elongation and reciprocated by a suitabledrive arrangement. Jaws on the slide are closed to engage the materialwhile the slide moves in one direction and release the material duringopposite movement of the slide. The jaws are operated in synchronizationwith the slide movement.

The force required for closing the jaws is relatively high, and istransmitted tothe slide in the known devices in such a manner as toincrease the contact pressure between the slide and the guides whichhold the slide in the desired path during its reciprocating movement.Wear of the engaged guiding surfaces is an important factor indetermining the useful life of the known feeding arrangements.

A primary object of this invention is the provision of a feedingapparatus of the type described which is free from the shortcomings ofthe known devices and has a long and troublefree life.

Other features, additional objects, .and many of the attendantadvantages of this invention will readily become apparent from thefollowing detailed description of a preferred embodiment when consideredin connection with the appended drawing in which:

FIG. 1 shows a feeding apparatus of the invention in top plan view; and

FIG. 2 illustrates the apparatus of FIG. 1 in sideelevational section onits vertical plane of symmetry.

Referring now to the drawing in detail, there is seena slide I mountedon two round guide bars 41, 42. The moving mechanism which reciprocatesthe slide 1 on the bars 41, 42, as indicated by a double arrow in FIG.1, includes a circular disc 12 mounted on an upright drive shaft 16which is turned at uniform speed counterclockwise, as viewed in FIG. 1,during operation of the apparatus. The disc 12 functions as the web of acrank drive also including a crank pin 18 whose axis is parallel to andoffset from the axis of the drive shaft 16.

A tubular elongated connecting rod 29 is'provided with a fixed bottomend bearing 9 which engages the pin 18 for angular movement of the rod29 about the axis of the pin 18. A rubber sleeve 10 is interposedbetween the bearing shell and the body of the bottom end bearing 9 topermit very limited movement of the crank pin 18 while the connectingrod 29 stands still.

The top end of the connecting rod 29 is secured to the slide 1 by ahinge arrangement which permits the rod 29 to pivot about yet anotheraxis parallel to the afore-mentioned axes of the shaft 16 and the crankpin 18. The hinge arrangement includes a bracket 6 which is secured tothe slide 1 by a hinge pin 11 and may swing in an opening 20 of theslide 1 while threadedly attached to the connecting rod 29.

In the illustrated condition of the apparatus, the path of the slide 1,which is determined by the guide bars 41, 42 and rectilinear, isparallel to a line or plane drawn through the axes of the shaft 16, thecrank pin 18, and the hinge pin 1 1.

A fixed clamping jaw 38 on the slide 1 cooperates with a movable jaw 32pivotally mounted on the slide 1 to define a passage 2 whose width isnarrowest in the illustrated position of the apparatusand slightlynarrower than the thickness of the material that it is desired to feed,the jaws illustrated being particularly suitable for flat wire or stripof metal or other slightly resilient stock.

The operating mechanism which holds the jaw 32 in the illustratedposition closely adjacent the fixed jaw 38 while the slide moves awayfrom the-disc '12, and holds the jaw 32 sufficiently remote fromthe jaw38 during movement of the slide in the opposite direction to release thematerial being fed includes a radial cam 23 fixedly mounted on the crankweb or disc 12 in coaxial relationship to the crank pin 18 by a flangedsleeve 21 fixed on the crank pin 18.

An elongated, round, operating bar 28 is longitudinally slidablyreceived in the bore of the tubular connecting rod 29. A fork 37 fixedlyattached to one terminal portion of the operating bar 28 carries a camfollower roller 24 which is held in rolling contact with the cam face ofthe cam 23 by a helical compression spring 27 coiled about theafore-mentioned terminal portion of the bar 28 and abuttingly interposedbetween respective surfaces of the bottom end bearing 9 and the fork 37.It will be appreciated that the bottom end bearing 9 and the top end ofthe connecting rod 29 are on a common horizontal level in theillustrated apparatus, and that the terms bottom end and top en aremerely chosen by analogy to automotive applications to designate theends of a connecting rod near and remote from a crank pin respectively.

The other terminal portion of the operating bar 28 carries awedge-shaped cam 4 which slides on a guide face of the bracket 6. Theunderside of the movable jaw 32 is provided with a recess 39 whichconforrningly receives a bearing ball 31. The downward movement of theball 31 out of the recess 39 is limited by a metal strip 33 providedwith an opening 5 only slightly smaller than the largest cross sectionof the ball 31, but sufiicient to permit engagement of the ball with theface of the cam 4 obliquely inclined relative to the direction ofelongation of the bar 28 in all operative positions of the cam. A strongleaf spring 30 has one end fixedly attached to the bracket 6 while thefree end abuts against the jaw 32 and biases the jaw away from the fixedjaw 38, thereby holding the ball 31 engaged with the earn 4.

The crank pin 18 is fixedly mounted on a slide 40 received in dovetailengagement between two segmentshaped guide plates 15. The guide platesare fastened to the disc 12 by clamping screws 35, 36 which pass througharcuate slots in the guide plates and therefore permit limited angularadjustment of the guide plates. The position of the slide 40 in thedovetail slot extending along a diameter of the disc 12 between theguide plates 15 is determined by a threaded spindle l7 engaging athreaded bore in the slide 40 and rotatably secured against axialmovement in a yoke 19 which connects the guide plates 15 at one end ofthe dovetail slot. When the spindle 17 is turned, the axis of the crankpin 18 is shifted toward or away from the axis of the drive shaft 16 tovary the throw of the crank drive, and thereby to vary the length of thewire increments fed during each cycle of reciprocating movement of thecrank l. v

The cam 23, as is best seen in FIG. 1, has a cam face which extends in aclosed loop about the axis of the crank pin 18. The cam face has twoalmost semicircular sections of different radius connected by steep,short flanks.

As shown in FIG. 1, the slide 1 is in its end position most remote fromthe axis of the drive shaft 16, and the cam follower roller 24 holds theoperating bar 28 against the force of the springs 27 and 30 (FIG. 2) insuch a position that the ball 31 engages the highest point on theobliqueface of the cam 4, thereby holding the movable jaw 32 closely adjacentthe jaw 38. The

passage 2 is at its smallest cross section. The cam follower 24. abutsagainst the face portion of the cam 23 of larger radius.

When the shaft 16 turns the disc 12 counterclockwise from the positionshown in FIG. 1, the cam follower roller 24 drops to the face portion ofthe cam 23 of smaller radius, thebar 28 is moved toward the shaft 16 bythe combined effects of the springs 27 and 30, the ball 31 rollsdownward along the oblique face of the earn 4 and thereby permits thespring30 to pivot the jaw 32 away from the jaw 38. During continuedrotation of the shaft 16 and of the attached disc 12, the connecting rod29 pulls the slide 1 toward the shaft 16, and the opened jaws 32, 38slide along the non-illustrated, releasedflat wire or strip received inthe passage 2. When the disc 12 has turned through an angle of 180, theslide 1 is nearest the shaft 16, the cam follower roller 24 returns tothe cam face portion of greater radius on the cam 23, and the jaws 32,38 are closed about the non-illustrated wire or strip. During subsequentreturn of the apparatus to the illustrated position, the wire or stripis taken along and fed forward, that is, to the left as viewed in thedrawing.

Because the axes of the drive shaft 16, the crank pin 18, and the hingepin 11 are aligned in the direction of slide movement on the guide bars41, 42, the slide 1 moves in its rectilinear path only to a minimalextent while the disc 12 moves into and out of the position shown in thedrawing. The jaws .32, 38 are being opened and closed during the feedingcycle .while the slide 1 almost stands still. If so desired, stops (notillustrated) may be provided to engage the slide 1 immediately before itwould normally reach the end positions of its stroke of which only oneis seen in the drawing. The shortening of the slide stroke, without anyother changes in the apparatus, results in compression of the rubbersleeve 10, and the compressibility of the sleeve determines the lengthby which the stroke of the slide 1 may be shortened. When the slide 1engages one of the non-illustrated stops, it stands still while thecrank pin 18 continues turning about the axis of the shaft 16, and thecam follower 24 travels along the face of the cam 23. The jaws 32, 38thus are opened and closed whilethe slide 1 is stationary, a mode ofoperation which is often desirable.

While the sleeve 10 hasbeen shown to be interposed between theconnecting rod 29 and the crank pin 18, it may obviously be providedanywhere else in the motion transmitting train connecting the crank web12 and the slide 1 and constituted essentially by the crank pin 18, theconnecting rod 29, and the hinge arrangement including the bracket 6 andthe hinge pin 11, without significantly affecting its operation.

Other modifications and variations of the present invention are possiblein the light of the above teachings. It is therefore to be understoodthat, within the scope of the appended claims, the invention may bepracticed otherwise than as specifically described.

What is claimed is:

1. A feeding apparatus for wire and like elongated material comprising,in combination:

a. a slide member;

b. guide means guiding said slide member in a path;

c. moving means for reciprocating said slide member in said path betweentwo terminal positions, said moving means including 1. a crank webmember,

2. drive means for rotating said crank web member about a first axis,

3. a crank pin member on said crank web member, said crank pin memberhaving a second axis spaced from said first axis,

4. a tubular, elongated connecting rod having one end portion engagingsaid crank pin member for angular movement about said second axis, and

5. hinge means securing the other end portion of said connecting rod tosaid slide member for pivoting movement about a third axis;

. two clamping jaw members mounted on said slide member; and I operatingmeans for holding one of said jaw members adjacent the other jaw memberwhile said slide member moves in one direction in said path thereof, andfor holding said one jaw member remote from said other jaw member whilesaid slide member moves in the opposite direction, said operating meansincluding 1. a cam member mounted on said crank web member,

2. an elongated operating member longitudinally movable in saidconnecting rod,

3. cam follower means operatively connected to one longitudinallyterminal portion of said operating member and. engaging said cam member,and

4. connecting means connecting the other terminal portion of saidoperating member to said one jaw member.

2. An apparatus as set forth in claim 1, wherein said path issubstantially rectilinear and parallel to a line through said second andthird axes when said slide member is in one of said terminal positions.

3. An apparatus as set forth in claim 1, wherein said cam member has acam face extending in a closed loop, two portions of said cam face beingsubstantially semicircular about said second axis and of differentradius.

4. An apparatus as set forth in claim 3, wherein said cam follower meansinclude a cam follower member mounted on said one terminal portion andyieldably resilient means biasing said cam follower member towardengagement with said cam face.

5. An apparatus as set forth in claim 3, further comprising adjustingmeans for shifting said crank pin member relative to said crank webmember and for thereby varying the spacing of saidfirst and second axes.

6. An apparatus as set forth in claim 5, wherein said crank pin member,said connecting rod, and said hinge means jointly constitute members ofa motion transmitting train connecting said crank web member to saidslide member, said train further including a resilient buffer interposedbetween two members of said train for permitting limited movement ofsaid crank web member while said slide member stands still.

7. An apparatus as set forth in claim 1, wherein said one jaw member ismovably mounted on said slide member, the other jaw member being fixedlymounted on said slide member.

8. An apparatus as set forth in claim 7, wherein said

1. A feeding apparatus for wire and like elongated material comprising,in combination: a. a slide member; b. guide means guiding said slidemember in a path; c. moving means for reciprocating said slide member insaid path between two terminal positions, said moving means including 1.a crank web member,
 2. drive means for rotating said crank web memberabout a first axis,
 3. a crank pin member on said crank web member, saidcrank pin member having a second axis spaced from said first axis,
 4. atubular, elongated connecting rOd having one end portion engaging saidcrank pin member for angular movement about said second axis, and 5.hinge means securing the other end portion of said connecting rod tosaid slide member for pivoting movement about a third axis; d. twoclamping jaw members mounted on said slide member; and e. operatingmeans for holding one of said jaw members adjacent the other jaw memberwhile said slide member moves in one direction in said path thereof, andfor holding said one jaw member remote from said other jaw member whilesaid slide member moves in the opposite direction, said operating meansincluding
 1. a cam member mounted on said crank web member,
 2. anelongated operating member longitudinally movable in said connectingrod,
 3. cam follower means operatively connected to one longitudinallyterminal portion of said operating member and engaging said cam member,and
 4. connecting means connecting the other terminal portion of saidoperating member to said one jaw member.
 2. drive means for rotatingsaid crank web member about a first axis,
 2. an elongated operatingmember longitudinally movable in said connecting rod,
 2. An apparatus asset forth in claim 1, wherein said path is substantially rectilinear andparallel to a line through said second and third axes when said slidemember is in one of said terminal positions.
 3. An apparatus as setforth in claim 1, wherein said cam member has a cam face extending in aclosed loop, two portions of said cam face being substantiallysemicircular about said second axis and of different radius.
 3. camfollower means operatively connected to one longitudinally terminalportion of said operating member and engaging said cam member, and
 3. acrank pin member on said crank web member, said crank pin member havinga second axis spaced from said first axis,
 4. a tubular, elongatedconnecting rOd having one end portion engaging said crank pin member forangular movement about said second axis, and
 4. connecting meansconnecting the other terminal portion of said operating member to saidone jaw member.
 4. An apparatus as set forth in claim 3, wherein saidcam follower means include a cam follower member mounted on said oneterminal portion and yieldably resilient means biasing said cam followermember toward engagement with said cam face.
 5. An apparatus as setforth in claim 3, further comprising adjusting means for shifting saidcrank pin member relative to said crank web member and for therebyvarying the spacing of said first and second axes.
 5. hinge meanssecuring the other end portion of said connecting rod to said slidemember for pivoting movement about a third axis; d. two clamping jawmembers mounted on said slide member; and e. operating means for holdingone of said jaw members adjacent the other jaw member while said slidemember moves in one direction in said path thereof, and for holding saidone jaw member remote from said other jaw member while said slide membermoves in the opposite direction, said operating means including
 6. Anapparatus as set forth in claim 5, wherein said crank pin member, saidconnecting rod, and said hinge means jointly constitute members of amotion transmitting train connecting said crank web member to said slidemember, said train further including a resilient buffer interposedbetween two members of said train for permitting limited movement ofsaid crank web member while said slide member stands still.
 7. Anapparatus as set forth in claim 1, wherein said one jaw member ismovably mounted on said slide member, the other jaw member being fixedlymounted on said slide member.
 8. An apparatus as set forth in claim 7,wherein said connecting means include a cam member having a cam faceobliquely inclined relative to the direction of elongation of saidoperating member and mounted on said other terminal portion, said onejaw member being mounted on said slide member for pivoting movement, andcam follower means on said one jaw member movably engaging saidobliquely inclined cam face.
 9. An apparatus as set forth in claim 8,wherein said connecting means further include yieldably resilient meansbiasing said one jaw member away from said other jaw member.